The current methods of treating blockages in blood vessels include Percutaneous Transluminal Coronary Angioplasty (PTCA). The PTCA includes use of angioplasty balloons, Drug Eluting Stents (DESs) and Bare Metal Stents (BMSs).
In instances where the angioplasty balloons are used for treating the blockages, the inflation of the angioplasty balloons may stretch luminal layers of the blood vessel thereby resulting in inflammation at the site of treatment. The inflammation may further lead to restenosis thereby delaying healing of the blood vessel. In addition to the angioplasty balloons, the BMSs are also used post angioplasty.
The BMSs are generally covered by the tissues of the blood vessel in a timely manner. Thus, proper endothealisation may be achieved in case of the BMSs. However, because of the body's immune response to the BMSs and because of the injuries that may occur while deploying the BMSs, instances of inflammations may occur. The inflammations may eventually lead to restenosis.
As compared to the BMSs, the use of the DESs is associated with reduced instances of restenosis. However, the DESs coated on the inner surface with drugs may not allow the tissues of the blood vessel to cover the DESs thereby leading to improper endothealisation and delayed healing. Therefore, the use of the DESs is associated with problems like partial endothealisation and improper formation of extracellular matrix. The partial endothealisation and improper formation of extracellular matrix may further lead to delayed healing of the blood vessel thereby leading to unpredictable outcomes. The unpredictable outcomes may include sub-acute thrombus formation and late catch up that is not observed with the BMSs.
Additionally, the currently used DESs are coated with an anti-proliferative or immunosupressive drugs on an inner surface as well as an outer surface of the DESs. The anti-proliferative or immunosupressive drugs have the property of blocking a proliferation cell cycle of the tissues of the blood vessel. Further, the current DESs employ polymers for loading the drugs on the DESs. The use of polymers results in inflammation at the site of deployment of the DESs. The polymers also lead to complications like, improper coverage of the lesions in the blood vessel, improper release of the drug from the DESs, poor in-tissue drug release and in-tissue drug diffusion, thrombus formation, delayed healing, improper healing, focal restenosis and edge restenosis. The use of the polymers may not facilitate the tissues of the blood vessel to cover the DESs completely and in a timely manner thereby leading to poor endothealisation.
Further, because of the above-mentioned complications associated with the DESs, the patients are often prescribed with a long-term anti-platelet therapy that may extend up to the lifetime of the patient. This post-deployment drug regime has its own side effects and complications.
Therefore, there is a need in the art for an improved method for healing the blood vessels post deployment of the DESs. Further, there is need in the art for a medical device that can improve the performance of the DESs.